Differential pressure well packer



April 6, 1954 c. c. BROWN 2,674,315

DIFFERENTIAL PRESSURE WELL PACKER Filed sept. 17, 1949 3 Sheets-Sheet l April 6,' 1954 c. c. BROWN 2,674,315

DIFFERENTIAL PRESSURE WELL PACKER Filed Sept. 17, 1949 3 Sheets-Sheet 2 C/cero .C Brown INVENTOR.

ATTORNEY April 6, 1954 C. c. BROWN 2,6'PL315y DIFFERENTIAL PRESSURE WELL PACKER Filed Sept. 17, 1949 3 Sheets-Shawl:I 3

{Q2/@Jg ATTORNEY Patented Apr. 6, 1954 UNITED STATES PATENT QFFICE 7 Claims.

This invention relates to well packers, and particularly to a well packer which is especially adapted for use in the dual completion of oil and gas wells.

Dual completion of oil and gas wells contemplates the completion and equipping of a well to permit the production of oil or gas, or both, simultaneously from two different producing earth formations or zones traversed by the same well bore, the producing zones being separated from each other ordinarily by a non-producing section of earth strata. In accordance with conventional practice, dual completion is normally effected by installing a suitable sealing means, such as a packer, in the well casing between the two producing zones to isolate one from the other. Communication is then established between both producing zones and the well and the uids from the two zones are then caused to flow in separate streams through concentric pipes extending into the well, one stream flowing through the inner pipe or tubing, and the other through the annular space between the tubing and the outer pipe or casing.

Satisfactory dual completion of wells has heretofore been diilicult to accomplish due to the unavailability of a suitable mechanical seal, which is eiectve under high pressure differentials in either direction, for effectively isolating the production from one zone from that of the other. So long as the pressure differentials between the producing zones are relatively low, i. e., below about 1000 pounds per square inch, and the upper zone is the high pressure Zone, almost any of the conventional production packers will meet the requirements with a reasonable degree of effectiveness. However, when the differential pressures exceed 1000 to 1500 pounds per square inch and the lower Zone is the higher pressure zone, isolation of the two zones from each other becomes practically impossible when employing most of the conventional types of production packers. The production type packers which are available which will successfully withstand these higher pressure differentials are of a type which, when once installed in the well bore, are not retrievable, and must be drilled up or otherwise completely destroyed in case their removal is required, a not infrequent occurrence.

Accordingly, this invention has for its principal objects the provision of an improved production packer which is particularly adapted for dual completion of wells; which forms an eincient seal under high diierential pressures in either direction; which is readily retrievable from the well;

which is of relatively simple construction; and which is operable with relatively little compression load from the tubing string.

Another object is the provision of an auxiliary jarring mechanism of relatively simple form for aiding in the release of the packer under certain conditions.

Other and more specic objects and advantages of this invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings which illustrate one useful embodiment in accordance with this invention.

In the drawings:

Figs. l, 2 and 3, taken together, comprise a longitudinal, generally quarter-sectional view of a packer structure in accordance with one eme bodiment of this invention, showing the packer structure mounted on a string of operating tubing and inserted in a well casing, and showing the parts thereof in their relative positions prior to setting of the packer;

Fig. 4 is a cross-sectional View along line 4-4 of Fig. 2;

Fig. 5 is a detail in perspective of the jarring mechanism forming a part of the packer; and

Figs. 6 and 7, taken together, comprise a view similar to Figs. 1, 2 and 3, showing the parts in their relative positions when the packer has been set.

Referring rst to Figs. l to- 4, inclusive, the packer structure is shown inserted inside a conventional well casing II) in process of being lowered therethrough to the point at which it is to be set. The packer structure includes a generally tubular operating stem I I which is extended for relative rotative and longitudinal movement through the bore of a generally tubular packer body, indicated generally by the numeral I2, which is concentrically disposed about stem II. The upper end of stem II is externally threaded for attachment of a collar I3 of somewhat larger external diameter than the stem, thereby forming an annular downwardly facing shoulder I4 about the stem. The upper end of collar I3 is adapted to be screwed to the lower end of a string of tubing I5 which is employed to lower the packer in the well and to perform the primary operations for setting and releasing the packer, as will be described hereinafter. A number of radial openings I6 are provided through the wall of stem II at a point spaced below shoulder I4. Stem I I has an extension sub I1 of somewhat larger external diameter than stem II connected to the lower end thereof and forming an annular shoulder I1a about the upper end of sub I1. A collar I8 of the same external diameter as sub I1 is threadedly connected to the lower end of the latter and carries a pair of pin members I9-I9 which project from diametrically opposite sides of collar I8. A tail-pipe is screwed into the lower end of collar I8 and is adapted to be connected at its lower end to any of the conventional well tools, indicated at 2|, such as a formation testing tool, cementing tool, or the like, which it may be desired to connect below the packer structure in accordance with conventional practice.

Packer body I2 includes an upper sleeve 22 which carries an outwardly flaring, upwardly opening, annular, cup-type sealing element 23, of generally conventional form constructed of rubber or other similar resilient composition material, which is firmly attached to the exterior of sleeve 22 in any suitable manner, its outer periphery being fiared to normally make frictional contact with the inner wall of casing I0. Sleeve 22 is counterbored from its upper end to provide internally thereof an upwardly facing, annular shoulder 24 forming the bottom of an annular packing recess 25 for the reception of suitable and conventional compressible packing 26 which is adap-ted to form a iiuid tight seal between the sleeve and the exterior surface of stem II. An annular packing gland 21 is vdisposed in recess 25 in compressive relation with the upper end of packing 26 and is held against retraction from the recess by means of a locking ring 2S screwed into the upper end of sleeve 22. A tubular mandrel 29, surrounding stem II, is connected to the lower end of sleeve 22 below sealing element 23 and has a generally conical, downwardly tapering exterior surface 30. The lower end of mandrel 29 extends into the bore of a tubular cage 3l and is provided with a plurality of angularly spaced longitudinally extending slots 32 terminating at points spaced from the lower end of the mandrel. A corresponding number oi' pins 33 -project inwardly from the upper end of cage 3| into slots 32 to thereby forni a longitudinally slidable connection between mandrel 29 and cage 3I. This Vconnection is also adapted to prevent relative rotational movement between these members and the engagement of the pins with ythe lower ends of slots 32 serves to lock the mandrel against cornplete withdrawal from the cage. The lower end of mandrel 29 is adapted to rest on shoulder I'Ia when the `parts of the packer are locked in the unset position, as will be described hereinafter. Cage 3l is provided with a plurality of radial openings 34 having a corresponding number of wall-gripping slips 35 arranged for relative radial movement therein. Slips 35 have their inner surfaces 35 tapered upwardly and outwardly to generally complement tapered surface of the mandrel, whereby when the latter is moved downwardly relative to the cage, surface 39 will act on the tapered inner surfaces 36 of the slips in the usual manner to urge the slips radially outwardly relative to the cage and into engagement with the wall of casing I0. The outer surfaces of slips are provided with radially projecting teeth 31 `which may be of any suitable form adapted for gripping the casing wall. Each of the slips 35 is loosely held against complete expulsion from its window 34 by means of upper and lower spring clips 38-38, having one end rigidly seated in a suitable recess 39 formed in the adjacent outer face of cage 3I and having its opposite end projecting into the window into 4 a registering recess 40 formed in the adjacent end of the slip.

Extending `from the lower end of cage 3| is an elongated lower sleeve 4I concentrically surrounding the operating string comprising stem II, sub I1, collar IS and -tail pipe 20. Lower sleeve 4I carries a pair of axially spaced downwardly opening cup-shaped sealing elements 42-42 substantially identical in form and construction with sealing element 23, and adapted to make fricticnal contact with the Wall of casing I0. The interior of lower sleeve 4I is provided with an internal packing recess 43 opposite and slightly below the lowermost Asealing element 42, and contains packing 44 which is adapted to form a fluid-tight seal between the lower sleeve and the exterior surface of extension sub I1. By the provision of packing 26 and packing 44, axially spaced seals are thus formed between the packer body and the operating string at the opposite ends of vlthe packer body.

The exterior of lower sleeve 4I carries a plurality of angularly spaced resilient friction elements, such as bow springs 45, which are adapted to extend outwardly therefrom into yieldable frictional engagement with the inner wall of casing i0. Bow springs 45 function in the usual manner to hold the packer body stationary by frictional engagement with the casing to permit rotational and longitudinal movement of the operating string relative t0 the packer body.

The lower portion of sleeve 4I is provided on opposite sides thereof with a pair of J-slots, each comprising a laterally extending recess 4S opening at one end into a longitudinal, downwardly extending slot 41. The J-slots are adapted to receive pins I9 and cooperate therewith to lock the packer body to the operating string in the unset position `when pins I9 are engaged in lateral recesses 46 and -to release the operating string from the packer body for longitudinal movement relative thereto when the string is rotated in one direction relatively to the packer body suiciently to place pins I9 in registration with slots 41. In each of the slots 41 wall 48 opposite the open end of recess 4B is undercut to form an upwardly tapering shoulder 49 at a point below recess 4E. The upper end of wall 48 is also provided with a tapered portion 5U which slopes inwardly toward recess 45 and the upper corners of pins I9 adjacent wall 43 are inwardly tapered at 5I. By the described shaping of the J-slots and pins, these elements are designed to function as jarring elements in laddition to functioning as locking and release mechanism for the packer, as will vbe described hereinafter. This type of jarring connection is disclosed in copending U. S. applications Serial No. 771,752, now Patent No. 2,595,563, filed September 2, 1947, by Cicero C. Brown and John R. Bass, and Serial No. 100,224, filed June 20, 1949, by Cicero C. Brown.

In operation the above described packer structure will be connected to tubing string I5 and lowered thereby into casing I0. At this stage pins I9 will be engaged in recesses 46 of the J-slots to lock the parts of the packer structure in their unset positions illustrated particularly in Figs. 1, 2 and 3. As illustrated in these figures, mandrel 29 will be retracted relative to cage 3I and slips 35 will be in their contracted positions. Shoulder I4 will be well above the upper end of upper sleeve 22 and openings I6 will be withdrawn to a position above the upper sleeve to thereby provide communication between the bore of the operating string and the annular space between casing IU and the operating string above sealing cup 23. As the packer structure is lowered through casing I0, fluid usually present in the casing will be displaced upwardly through the bore of the operating string and will emerge through openings I6 into the annular space above the packer, thereby permitting the structure to pass through such fluid without hindrance thereby. Sealing elements 23 and 42 and bow springs 45 will be in frictional engagement with the casing wall but the weight of the structure will be suiiicient to easily overcome this relatively nominal frictional resistance to its downward movement.

When the packer structure has been lowered to the point in casing IEI at which it is to be set, tubing string I5 will be rotated from the top of the well in the appropriate direction, generally clockwise, to rotate pins I9 out of recesses 46 into registration with the upper ends of slots 41, through which pins l@ may descend as lowering of the operating string is continued (Fig. '7) The lower portion of the packer body comprising cage 3l, sleeve 4I and the several elements carried thereby, will be held stationary by the frictional engagement of bow springs 45 with the casing wall to permit this relative rotational and longitudinal movement of the operating string. Downward movement of the operating string relative to the packer body will be continued until shoulder I4 on stem II engages packing gland 21. The weight of the operating string will thus be transferred to upper sleeve 22, while openings I6 will descend through the packer body to a point between the seals formed by packings 26 and 44 (Fig. 6), thereby preventing further transfer of well fluid through the operating string from below the packer body to the annular space above the packer body.

As the weight of the descending operating string is applied to gland 21, this weight will be transferred through packing 26 to upper sleeve 22 forcing the latter downwardly and driving tapered surface 3l! of the mandrel into wedging engagement with the inner surfaces of slips 35, thereby forcing the latter outwardly into gripping engagement with the inner Wall of casing I6. Spring clips 38, due to their light construction, will bend outwardly under the radial force thus applied to the slips to permit the slips to engage in the described outward movement. With communication between the portions of the well bore above and below the packer cut off by the descent of openings I6 into the packer body between the seals formed by packings 2S and 44, the column of fluid in the well bore above sealing cup 23 will become available to act downwardly thereon to thereby supplement the downward force applied by the weight of the tubing string to upper sleeve 22 and will thereby increase the radial force exerted on slips 35 to increase their gripping engagement with the wall of casing I0. At the same time, any tendency of the packer body to move downwardly under the forces thus applied from above, will be resisted by the reaction of the column of fluid below the packer body which will act upwardly against the downwardly opening sealing cups l2--42 to force lower sleeve y4I and cage 3! in the upward direction, and the opposing forces thus created against the upper and lower sleeves 22 and 4I, respectively, will serve to further increase the setting forces applied to the slips.

When the slips have been set in the manner described, it will be evident that any increase in the pressure differential across the packer, whether in the upward or downward direction, will only serve to increase the gripping force of the slips on the casing thereby assuring that there will be no axial movement of the packer under any condition of unbalanced pressures across the packer. At the same time, sealing cups 23 and 42, by virtue of their outwardly flaring shape, will be expanded by the fiuid in contact therewith to form effective seals with the casing at the opposite ends of the packer. Increases in pressure in the annular space between the casing and tubing above cup 23 will merely tighten the seal formed by this cup at the upper end of the packer, while increases in pressure in the annular space below cups 42--42 will tighten the seals formed by these cups at the lower end of the packer.

With the packer set in the manner described, it will be seen that iiuid from formations below the packer structure may enter the tubing string through suitable openings in tool 2! and flow to the surface through the bore of tubing string I5. Since openings I6 will now be between the seals formed by` packings 26 and 44 within the packer body and also between the seals formed by sealing cups 23 and 42--42, any fluid emerging from openings I6 will be trapped between these seals and the remainder of the stream will flow up the tubing string to the surface. At the same time fluid from above the packer may now upwardly to the surface through the annular space between the casing and tubing above the packer.

When it becomes necessary to remove the packer from the well, the packer may be released by raising the operating string sufciently to raise pins I9 in slots 41 until the pins are again opposite recesses 46. As the pins ascend in slots 41 to point opposite recesses 46, the inwardly sloping surfaces 5!) will be engaged by the sloping surfaces 5I of the pin. The engagement of these sloping surfaces under the upward pull applied to the operating string will produce a camming action between the engaged surfaces which will act to produce rotational movement of the pins relative to sleeve 4I in a direction to urge the pins into recesses 46, thereby again locking the packer body to the operating string. As the pins travel upwardly toward surface '56, shoulder I1a will first contact the lower end of mandrel 29 thereby pushing the mandrel upwardly relative to slips 35 before pins enter recesses 46. Continuing upward pull on the operating string will then draw the entire packer structure from the well, unless teeth 31 have become so deeply embedded or otherwise afxed to the casing wall as to prevent such withdrawal without placing undue strain on the operating string.

In the latter event, the slips may be dislodged by jarring action produced between the operating string and the packer body in the following manner:

Pins I9 will be rotated out of recesses 46 in the manner previously described and the operating string will be lowered to cause pins I9 to descend to the lower ends of slots 41 (Fig. 7). The operating string will then be additionally rotated slightly in the unlocking direction to place pins I9 against outer wall 48 of the slots below upwardly sloping shoulders 49. The operating string is then raised until sloping surfaces 5l of the pins engage shoulders 49, momentarily preventing further upward movement of the operating string until sufficient tension has been built up in the operating string to overcome the frictional force between the upwardly sloping surfaces of pins 5I and shoulders 49 which normally tends to hold the pins in engagement with the shoulders. As soon as these frictional forces have been overcome pins I9 will slip off of shoulders 49 into slots 4l' and will thereupon effect sudden release of the operating string which, under the tensional force built up therein, will contract sharply in the upward direction. This sudden upward movement of the operating string will drive shoulder Ha. on the upper end of extension l1 upwardly with a sharp impact against the lower end of mandrel 29, driving the latter upwardly out of its wedging engagement with the slips and releasing the latter for retraction from the casing. Almost simultaneously but slightly behind this impact, pins I9 will strike sloping surface 50 applying a jarring impact to lower sleeve 4l and its attached cage 3| which will, in turn, impart a jarring blow to the lower ends of slips S5 sufiicient ordinarily to break these loose from the casing. rlhe impact of pins i9 with surfaces 50 will automatically rotate the operating string to rotate pins I9 into recesses 4S, in the manner previously described,

to thereby lock the packer body to the operating string in the released position. This jarring action may be repeated as often as necessary to effect release of the packer. It will be understood that the length of extension il will be so dimensioned relative to the length of slots 4l above shoulders 49 that the jarring impact will occur iirst between shoulder Ila and the lower end of the mandrel and second between pins i9 and surfaces 59.

From the foregoing, it will be evident that a packer structure has been provided in accordance with this invention which will form an extremely eicient and substantially immovable seal for a well bore, and which is particularly adapted for use in dual completion of wells, wherein it will form an eiiicient seal between formations, irrespective of the direction or magnitude of the pressure diierentials which may exist or develop therein, and which is readily retrievable for reuse.

Although the illustrative embodiment employs an arrangement of parts for setting the packer by downward movement of the operating stem and mandrel relative to the slips, it will be understood that by suitable reversal of parts in a manner which will be readily apparent to those skilled in the art of well packers, the packer structure in accordance with this invention may be designed to be set by upward movement of the operating string and mandrel.

It will be understood the various other and more conventional jarring arrangements may be employed in place of the specific form herein described and that various other alterations and modifications may be made in the details of the illustrative embodiment within the scope of the appended claims but without departing from the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

l. A well packer, comprising, a body insertible in a well bore and embodying telescopically inter-connected upper and lower tubular sections, a tubular stem slidable through the bores of said sections, a releasable connection between said stem and the lower section, friction means on said lower section engageable with the wall of the well bore to hold the lower section stationary relative to axial movement of said stem, well wall-gripping slips mounted for radial movement in said lower section, a downwardly tapering conical slip-expanding mandrel connected to the lower end of said upper section and extending into the interior of said lower section into and out of expanding engagement with said slips in response to axial movement of said upper section relative to said lower section, a longitudinally slidable retaining connection between said mandrel and the upper end of said lower section, abutment means carried by said stem engageable with said upper section to apply axial compression to said upper section in response to relative downward movement of said stem, internal seals between said sections and said stem on opposite sides of Said slips, sealing elements mounted on the exteriors of said sections in sealing engagement with the wall of said well bore on opposite sides of said slips, said sealing elements being shaped to be actuatable by uid pressure exerted from the opposite ends of said body to intensify the axial force tending to move said sections toward each other.

2. In a well packer including a tubular packer body insertible in a well bore and a tubular operating stem extending through the bore of said body releasably connected thereto for relative axial movement, said body comprising a pair of tubular sections telescopically interconnected for limited relative axial movement, one of said sections carrying radially movable well wall-gripping slips and a friction cage engageable with the vall of said well bore, a slip-expanding mandrel connected to the other of said sections for movement into and out of expanding engagement with f said slips in response to said relative axial move- .3 gagement with the wall of said well bore on opposite sides of said slips, said sealing elements being circumferentially spaced from said stem and comprising annular, outwardly flaring resilient cupshaped bodies opening toward the outer ends of their respective sections.

3. A well packer comprising a body insertible in a well bore embodying a pair of tubular sections telescopically interconnected for limited relative axial movement, friction means mounted on one of said sections and frictionally engageable with the well wall for holding said section stationary in said well bore relative to axial movement of the other section, radially movable well wall-gripping slips on one of said sections, a slip-expanding mandrel connected to the other of said sections for movement into and out of expanding engagement with said slips in response to said relative axial movement, annular sealing elements mounted on said sections expandible solely by iiuid pressures from opposite ends of said body into sealing engagement with the wall of said well bore on opposite sides of said slips, and means for sealing the bores of said sections on opposite sides of said slips.

4. A well packer comprising a body insertible in a well bore and embodying a pair of tubular sections telescopically inter-connected for limited relative axial movement, friction means mounted on one of said sections and frictionally engageable with the well wall for holding said section stationary in the well bore relative to axial movement of the other, radially movable well wallgripping slips mounted on said one of said sections, a slip expanding mandrel connected to the other of said sections for movement into and out of expanding engagement with said slips in response to said relative axial movement, a tubular operating stem slidable through the bore of said body and carrying an abutment member movable therewith into and out of axially compressive engagement with the outer end portion of the other one of said sections, internal seals between said sections and said stem, an upwardly facing shouider on said stem engageable with the inner end portion of said other one of said sections, a releasable bayonet-type connection between said stem and said one section longitudinally spaced from said shoulder, and sealing elements mounted on the exteriors of said sections in sealing engagement with the wall of said weil bore on opposite sides of said slips, said sealing elements being circumferentially spaced from said stem and shaped to be actuatable by fluid pressure exerted from opposite ends of said body to intensify the axial forces tending to move said sections toward each other.

5. A well bore sealing tool, comprising, a two section tubular body having the sections thereof telescopically inter-connected for limited relative axial movement, annular cup-seals mounted on the exterior of each of said sections and facing oppositely toward the outer ends thereof, radially movable well wall-gripping elements mounted on one of said sections between said seals actuatable by relative inward axial movement of said sections to move said slips to operative position, i

an operating member extending through said body having longitudinally spaced abutment members positioned thereon to engage longitudinally spaced portions of the respective sections when the latter are in relatively extended relation to releasably hold said sections in inoperative relation, and inner seals between said sections and said operating member on opposite sides of said well wall-gripping elements.

6. A well bore sealing tool, comprising, a twosection tubular body having the sections thereof telescopically inter-connected for limited relative axial movement, annular cup-seals mounted on the exterior of each of said sections and facing oppositely toward the outer ends thereof, radially movable well wall-gripping elements mounted on one of said sections between said seals, a mandrel connected to the other of said sections for movement into and out of expanding engagement with said well wall-gripping elements by the relative axial movement of said sections, and an operating member extending through said body having longitudinally spaced abutment members positioned thereon to engage longitudinally spaced portions of the respective sections when the latter are in relatively extended relation to releasably hold said sections in inoperative relation, and internal seals between said sections and said operating member on opposite sides of said well wall-gripping elements.

'7. A well bore sealing tool, comprising, a twosection tubular body having the sections thereof telescopically inter-connected for limited relative axial movement, annular cup-seals mounted on the exterior of each of said sections and facing oppositely toward the outer ends thereof, radially movable well wall-gripping elements mounted on one of said sections between said seals aotuatable by the relative axial movement of said sections, an operating member extending through said body having longitudinally spaced abutment members positioned thereon to engage longitudinally spaced portions of the respective sections when the latter are in relatively extended relation to releasably hold said sections in inoperative relation, said abutment members being successively engageable by relative axial movement between said operating member and the respective sections to produce successive jarring impacts thereon, and internal seals between said sections and said operating member on opposite sides of said well Wall-gripping elements.

References Cited in the le oi this patent UNITED STATES PATENTS Number Name Date 2,305,062 Church et al. Dec. 15, 1942 2,343,076 Otis et al. Feb. 29, 1944 2,496,546 Lamb Feb. 7, 1950 

